Heretofore, a number of recognized additives have been utilized as fire and/or smoke retardants in plastics or rubbers such as various metal oxides, for example zinc oxide, bismuth trioxide, molybdenum trioxide, litharge, vanadium pentoxide, tungstic oxide, cadmium oxide and antimony trioxide, various phosphorous compounds such as tricresyl phosphate, triphenyl phosphate, tributyl phosphate, tris(2-ethylhexyl)phosphate and tris(2,3-dichloropropyl)phosphate; various halogen containing compounds such as chlorinated waxes, antimony trihalides and antimony oxyhalides; and amine molybdates such as melamine molybdate, ammelimium beta-octamolybdate, dicyclohexylammonium alpha-octa-molybdate, didodecylammonium beta-octamolybdate and tripentylammonium decamolybdate.
Additionally, a variety of inorganic oxide glasses have heretofore been utilized such as a phosphate glass having a low softening point glass of Tg 300.degree. C. and optional blowing agent which is utilized in a reinforced thermosetting polymer as set forth in U.S. Pat. No. 3,933,689.
U.S. Pat. No. 3,935,018 relates to inorganic oxide glasses containing various ratios of P.sub.2 O.sub.5, B.sub.2 O.sub.3, and PbO compounds.
U.S. Pat. No. 4,079,022 relates to treating the moisture sensitivity of glass used as the reinforcing agent as well as the fire retarding resin by treating the surface with an alkaline solution of magnesium, calcium, barium, iron, aluminum, lead or zinc compounds.
U.S. Pat. No. 4,371,665 relates to the utilization of various sulfate glasses having components such as potassium sulfate in a polymer as a smoke retardant.
U.S. Pat. No. 3,931,064 relates to an isocyanate-based polymeric foam material having dispersed therein a particulate low-softening point inorganic oxide glass having a transformation temperature of not greater than 300.degree. C.
U.S. Pat. No. 4,137,199 relates to a mixture including an organic polymer and a phosphate glass.
However, none of the above patents relate to applicant's synergistic phosphate-sulfate glass composition.